Fertility of female mice fed coumestrol and diethylstilbestrol

Abstract

Coumestrol, a compound produced by various legumes which exerts estrogen‐like activity in animals, and diethylstilbestrol (DES) were studied as chemical agents for controlling reproduction in mice. Female mice were fed control diets or diets containing 100 ppm coumestrol for eight days. Female mice were exposed to males and reproductive tracts examined 14 days later. Litter size was not affected by 100 ppm dietary coumestrol but feed consumption was reduced 17%. Similar trials were conducted with mice fed 1 ppm DES. Vaginal plugs were present in 50% of the females fed 1 ppm DES, but no fetal pups were present. Feed intake was reduced 37% by the DES. Levels of 0, .1, .25, .50, .75 and 1.0 ppm DES were compared in two strains of mice, Swiss and ICR. Reproduction in both strains was totally inhibited by all DES treatments. The use of DES to control rodent populations warrants further investigation.     

Effect of squalane on hexachlorobenzene (HCB) concentrations in tissues of mice

Abstract

Female mice were given 100 mg HCB/kg body weight i.p. and fed diets containing 0, 2.5, 5.0, and 7.5% of squalane. After 3 weeks samples of livar, blood and abdominal fat ware analysed for HCB as well as for squalane. HCB concentrations were significantly lowered as comoared to controls in all tissues and at all dietary concentrations of squalane to a maximum of about 36% in fat, 44% in liver and 47% in blood. The effect of squalane upon HCB concentrations was strongly dose depedent in abdominal fat. In contrast, no significant differences were seen with liver and blood between animals fed 5.0 or 7.5% of squalane. Squalane was detected in considerable amounts in the livers (50–100 ppm) but r.ct in abdominal fat (<1 ppm) of mice fed squalane.     

Pentachlorotoluene and pentabromotoluene: Results of a subacute and a subchronic toxicity study in the rat

Abstract

Pentachlorotoluene (PCT) and pentabromotoiuene (PBT) are environmental contaminants detected in the Great Lakes ecosystem. In view of the paucity of toxicity data and the potential for human exposure, a subacute (28 day) and a subchronic (91 day) study were conducted in the rat. In the subacute study, groups of 10 male and 10 female rats were fed the diet containing PCT or PBT at 0, 0.5, 5.0, 50 or 500 ppm for 28‐days. In the subchronic study, the group size was increased to 15, the dose levels were 0, 0.05, 0.5, 5.0, 50 and 500 ppm in the diet and the exposure period was 91 days. Growth rate and food consumption were not affected by exposure to either chemical in the subacute and subchronic study. Clinical observations revealed no abnormalities. Decreased hemoglobin was observed in female rats fed 5.0 ppm PCT and higher levels in the subacute (28 day) study. In the same study the hematocrit value and erythrocyte numbers of females fed 5.0 or 500 ppm PCT diets were significantly lower than the control. In both subacute and subchronic studies mild dose‐dependent histopathological changes were observed in the thyroid, liver and kidney of rats fed PCT and PBT diets. In general male rats were more susceptible than females to the treatment of PCT and PBT. Based on these data, it was concluded that the no observable adverse effect level for PCT was 50 ppm in the diet (3.5 mg/kg b.w./day) and that of PBT was 5.0 ppm (0.35 mg/kg b.w./day).     

Pentachlorotoluene and pentabromotoluene: results of a subacute and a subchronic toxicity study in the rat

Pentachlorotoluene (PCT) and pentabromotoluene (PBT) are environmental contaminants detected in the Great Lakes ecosystem. In view of the paucity of toxicity data and the potential for human exposure, a subacute (28 day) and a subchronic (91 day) study were conducted in the rat. In the subacute study, groups of 10 male and 10 female rats were fed the diet containing PCT or PBT at 0, 0.5, 5.0, 50 or 500 ppm for 28-days. In the subchronic study, the group size was increased to 15, the dose levels were 0, 0.05, 0.5, 5.0, 50 and 500 ppm in the diet and the exposure period was 91 days. Growth rate and food consumption were not affected by exposure to either chemical in the subacute and subchronic study. Clinical observations revealed no abnormalities. Decreased hemoglobin was observed in female rats fed 5.0 ppm PCT and higher levels in the subacute (28 day) study. In the same study the hematocrit value and erythrocyte numbers of females fed 5.0 or 500 ppm PCT diets were significantly lower than the control. In both subacute and subchronic studies mild dose-dependent histopathological changes were observed in the thyroid, liver and kidney of rats fed PCT and PBT diets. In general male rats were more susceptible than females to the treatment of PCT and PBT. Based on these data, it was concluded that the no observable adverse effect level for PCT was 50 ppm in the diet (3.5 mg/kg b.w./day) and that of PBT was 5.0 ppm (0.35 mg/kg b.w./day).     

Effects of dietary zinc supplementation on hen performance, ammonia volatilization, and nitrogen retention in manure

This investigation was undertaken to evaluate the effects of dietary ZnSO4 supplementation on ammonia volatilization and nitrogen retention in hen manure. One hundred twenty, 45-wk-old commercial Leghorn laying hens were sequentially fed diets with 1000, 2000, and 3000 ppm Zn as ZnSO4 (Zn-1000, Zn-2000, and Zn-3000), then followed by two control dietary periods with 114 ppm Zn (Control-1 and Control-2) for a total of five consecutive eight-day experiment periods, respectively. When hens were fed the 1000 and 2000 ppm Zn treatment diets, room ammonia levels were significantly reduced compared to the control diets. Dietary Zn treatments reduced the decomposition of uric acid, resulting in an increase in manure total-N retention compared to the control fed birds. The 1000 ppm Zn supplement had no adverse effects on hen body weight, feed consumption, egg production, egg weight, albumen height, or shell thickness. However, hens fed the diet containing 3000 ppm Zn had significantly depressed body weight, feed consumption, egg production, egg weight, and shell thickness. Zinc levels of egg contents increased linearly as dietary Zn levels increased. These levels in eggs would not be a problem for human consumption because these are much less than the daily Zn recommended dietary allowance. Although land application of such manure will not cause environmental problems or crop toxicity, proper monitoring of soil and crop Zn levels and effective nutrient management planning would be well advised.     

Long-term toxicology and carcinogenicity of 2,4,6-trichlorophenol

Carcinogenesis bioassays were conducted by giving 2,4,6-trichlorophenol [2,4,6-TCP] in feed to groups of 50 male and female Fischer rats and male B6C3F1 mice for two years. Dietary concentrations were 0 [20/group], 5000 [0.5%], or 10,000 [1%] ppm. Female mice began with 10,000 and 20,000 ppm but after 38 weeks were lowered due to reduced body weights to 2500 and 5000 ppm for 67 weeks; exposures averaged 5200 and 10,400 ppm. Adverse effects at two years were leukocytosis and monocytosis of peripheral blood and hyperplasia of bone marrow in both sexes of rats. In mice, liver toxicity, including individual liver cell abnormalities, focal areas of cellular alteration, and focal and nodular areas of hyperplasia were commonly present. Regarding carcinogenic activity, TCP caused leukemias/lymphomas in male rats, and possibly in female rats and female mice as well, and induced liver tumors in male and female mice. Using NTP categories of evidence indicates ‘clear evidence of carcinogenicity’ for male rats [hematopoietic system tumors]; ‘equivocal evidence of carcinogenicity’ for female rats [hematopoietic system tumors]; ‘clear evidence of carcinogenicity’ for male and female mice [liver tumors].     

Comparison of the effects of seleno-L-methionine, seleno-DL-methionine, and selenized yeast on reproduction of mallards

The toxicities of seleno-L-methionine, seleno-DL-methionine, and selenized yeast were compared. Ten pairs of mallards were fed a control diet and 15 pairs were fed diets containing 10 ppm selenium as seleno-DL-methionine, seleno-L-methionine, or selenized yeast. Hatching of fertile eggs was significantly lower for females fed 10 ppm selenium as seleno-DL-methionine (7.6%) and seleno-L-methionine (6.4%) than for controls (41.3%). Survival of ducklings was lower when their parents had been fed 10 ppm selenium as seleno-L-methionine (20.0%) than for controls (98.4%). The number of 6-day-old ducklings produced per female was significantly lower for mallards fed 10 ppm selenium as seleno-DL-methionine (0.47) or selenized yeast (2.67) than for controls (6.10), and was significantly lower for mallards fed seleno-L-methionine (0.13) than for mallards fed selenized yeast. The eighth eggs of females fed the DL or L forms of selenomethionine contained means of 9.2 and 8.9 ppm selenium, wet weight; these means were higher than the mean (6.6 ppm) for females fed selenized yeast. Among embryos that died at 7 days of age or older, the percentage of embryos that were deformed was 1.3% for controls, 24.6% for seleno-DL-methionine, 28.2% for seleno-L-methionine, and 11.0% for selenized yeast. The results suggested that seleno-DL-methionine and seleno-L-methionine were of similar toxicity and were both more toxic than selenium from selenized yeast.     

Residues of lindane and its metabolites in eggs, chicks, and body tissues of hen pheasants after ingestion of lindane-14C via treated wheat seed or gelatin capsules.

Studies were carried out to investigate possible contamination of pheasants with residues of lindane used as seed dressings for the control of wireworms in cereal crops. One group of laying hen pheasants was fed 20 mg of lindane-14C in gelatin capsules while another group was fed wheat seed treated with 100 ppm of lindane-14C for 15 days. Residues in eggs were monitored for about 70 days. Residues in chicks hatched from the eggs were also measured. Concentrations of residues in muscle, liver, brain, and fatty tissues were determined at various times. 14C-labeled residues in eggs increased sharply in the capsule treated group and reached an average maximum of about 19 ppm in 8 days. This level decreased to less than 0.5 ppm in about 50 days. Residues in eggs from the pheasants fed treated seed increased gradually to an average maximum of 17 ppm 22 days after commencement of the feeding program. This level decreased to less than 0.5 ppm 50 days later. Residues in hatched chicks were significantly lower than those in the eggs. Highest concentrations of residues were found in fatty tissues which decreased to non-detectable level in 6 months. Several chlorobenzene metabolites were identified in egg yolk and chick tissues. Chlorophenolic metabolites were indicated only in chicks.     

Induction of rat hepatic microsomal enzymes by toxaphene pretreatment

Abstract

The effects of pretreatment of rats with toxaphene on hepatic drug metabolizing enzymes and several other parameters of the mixed function oxidase system were investigated. Adult male Sprague‐Dawley rats were fed diets containing 0, 50, 100, 150 and 200 ppm of toxaphene for 14 days. The body weight gain was unaltered as well as the food consumption in all the toxaphene fed groups. There was no change in the weights of brain, kidney, heart, and testes but the liver weight was significantly increased. The thymus weight in all the toxaphene fed groups was decreased. Hydroxylation of pentobarbital and aniline was significantly enhanced in rats exposed to toxaphene. Ethylmorphine‐N‐demethy‐lase activity in the toxaphene treated rats was also elevated. Enhanced hydroxylation of pentobarbital was also evident from the decreased sleeping time following pentobarbital administration. Exposure to toxaphene increased cytochrome P‐450, NADPH‐cytochrome c‐reductase and dehydrogenase in hepatic microsomal fractions. The binding of aniline and hexobarbital to microsomes was also enhanced, suggesting that the intermediate steps in the electron‐transfer system were increased. In conclusion, pretreatment of rats with toxaphene for fourteen days resulted in the induction of the hepatic mixed function oxidase system.     

Bioavailability and biological activity of wheat-bound chlorpyrifos-methyl residues in rats.

Wheat grain was treated with 14C-chlorpyrifos-methyl to generate bound residues for determining their bioavailability to rats. In a parallel experiment, bound residues were prepared with non-labelled chlorpyrifos-methyl to determine possible adverse effects in rats fed the grain-bound residue for 28 and 90 days. Two dose levels of 10 and 50 ppm were initially used on the grain. The 10 ppm led to the formation of 25.1% bound residues (2.51 ppm) after 6 months as determined by radiomeasurement. The higher dose was assumed to form 12.55 ppm bound residues. When 14C-bound residues were fed to male rats for 24 hours, the animals eliminated 75% of the radioactivity in urine, 7% in expired air and 8% in faeces after 3 days, indicating that the bound residues were highly bioavailable. A further "bioavailable" amount (4%) was found in selected organs.     

Effect of maternal dietary hexachlorocyclohexane exposure on pup survival and growth in albino rats.

In adult albino rats, maternal dietary beta- and gamma-hexachlorocyclohexane (HCH) intake during gestation upto 400 ppm level did not affect the number of litters produced. But about 50 and 100% pup mortality was found in 200 and 400 ppm beta-HCH group within 5 days of birth. Maternal mortality was observed in 800 ppm beta-HCH group during third week of gestation. The effect of maternal dietary intake of HCH isomers at 50 and 250 ppm level during gestation and/or lactation on perinatal development was also studied. The body weights and sizes of the newborn litters of mother rats exposed to dietary HCH isomers did not differ from controls. Similarly, the growth and development of the litters of HCH exposed mother rats that survived 28 day lactation period were found to be comparable to controls as evidenced by the body weight and weight of vital organs. However, liver weight increases were found in the 28 days weaned litters wherever the mothers had been exposed to HCH isomers during lactation. Lowered kidney weight was seen in litters of mother rats fed 250 ppm gamma-HCH during gestation and lactation. The brain and testis weights were not affected in the litters of any experimental groups.     

Cobalt induced changes in immune response and adenosine triphosphatase activities in rats.

The immuno-biochemical effects of cobaltous chloride in rats receiving iron-sufficient and deficient diets were investigated. Rats receiving 100 ppm or more cobalt showed a significant reduction in thymus and body weights along with a marked decrease in hemoglobin, hematocrit, sheep agglutinins and plaque forming cells. These effects were more pronounced in rats receiving cobalt mixed with iron-deficient diet than those fed on iron-sufficient diet. The Na+-K+ and mitochondrial (Oligomycin-sensitive) Mg2+ATPase activities in brain and liver of rats fed with iron-deficient diets were decreased significantly. However, the ATPase activities in these tissues from rats fed with cobalt mixed with iron-sufficient diets were not altered.     

Efficacy of the botanical extract (myrrh), chemical insecticides and their combinations on the cotton leafworm, Spodoptera littoralis boisd (Lepidoptera : Noctuidae)

Effects of the botanical extract (myrrh), Commiphora molmol, and the sublethal treatments of profenofos/chlorofluazuron, fenvalerate and pyriproxyfen on the larvae of S. littoralis were investigated. The results showed that myrrh induced the highest activity after 7 days of treatment with concentration of 10000 ppm and the percentage of mortality reached 44.4%. The chemical insecticide profenofos/chlorofluazuron appeared to be the most effective treatment, giving a mortality of 54% after one day of treatment with a concentration of 100 ppm. Different treatments showed adverse effects on pupation, emerging adults and larval duration. The highest concentration of myrrh (10000 ppm) induced 35% pupation. No pupa was obtained with profenofos/chlorofluazuron while fenvalerate and pyriproxyfen gave 13.3% at 50 ppm. At 10000 ppm of myrrh, 25% adult was emerged, also fenvalerate and pyriproxyfen decreased the emerging moth to 13.3% at 50 ppm. For control there was no larval mortality at 7 days and the percentages of pupation and adult emergence were 90%. Bioassays were also conducted to test the joint action of myrrh applied in binary mixtures with each chemical insecticide on Spodoptera larvae. Results of the bioassay of mixtures indicated antagonistic effects on larval mortality. However, combination of myrrh with profenofos/chlorofluazuron showed additive effect. Also, the degree of pupation and emerging moth varied considerably when myrrh combined with the chemical insecticides. The present work shows the strong efficacy of the botanical extract (myrrh) which could be used alone or in combination with sublethal doses of certain insecticides to control the cotton leafworm.     

Effect of cadmium on ATPase activities in rats fed on iron-deficient and sufficient diets

Male Sprague-Dawley rats were fed on different levels of cadmium mixed with purified diets containing iron or no iron for 8 weeks. The body weight gain, tissue weights, hemoglobin, hematocrit, liver and brain ATPase were measured at 2, 4 and 8 weeks after feeding. The hemoglobin and hematocrit values were the same in all rats fed on cadmium. The rats fed on iron-deficient diets mixed with cadmium showed a significant decrease in body weight gain. However, the rats receiving only the 100 ppm of cadmium in iron-sufficient diet showed a significant decrease in body weight gain. There were no significant changes in the weights of thymus, spleen, kidney, heart, brain and testes. However, the liver weights were decreased in the highest treatment of cadmium but the liver weight/body ratios were uneffected. Na+-K+ activated ATPase activity in brains of rats fed on cadmium were significantly decreased at 2, 4 and 8 weeks of treatment. The decrease was more pronounced in rats fed on iron-deficient diets. Oligomycin-sensitive (Mitochondrial) Mg2+ ATPase activity was also significantly decreased in liver and brain tissues of rats fed on cadmium. Oligomycin-insensitive Mg2+ ATPase activity, however, was not altered in any tissues tested. It appears that cadmium may be interfering with energy (ATP) production and utilization processes in rat brain and liver tissues.     

Effect of dietary protein on the distribution of cadmium,zinc and copper in rats following the oral administration of cadmium

Cadmium, 100 μg/rat/day, was administered orally 100 times (total amount of Cd administered, 10 mg), under conditions of low protein intake. The total amount of Cd in the liver and kidneys was as follows: females fed 20% protein diets > females fed 5% protein diets > males fed 20% protein diets ≒ males fed 5% protein diets. A decreased Zn concentration was found in the liver of males and the pancreas of males and females fed with the 5% protein diet. The Cu concentration in the kidneys was markedly influenced by low protein intake.     

Reproduction in mice treated with crufomate: effects of dermal treatments on female mice and on their progeny.

Dermal treatments with crufomate 100 or 50 mg/kg or crufomate vehicle 100 mg/kg were applied to mice either on days 35 and 21 before mating or on days 70, 56, 35, and 21 before mating. Two, but not four dermal treatments, with both doses of crufomate reduced the mating reponse and conception rate in mice. The mice either did not produce a litter or the litter died before the age of 7 days. Four treatments with crufomate 100 mg/kg, but not with 50 mg/kg, reduced the weaning weight of progeny weaned at the age of 21 days. The vehicle had no effects on reproduction and increased the weights at maturity of female and male progeny of mice given two and four treatments, respectively.     

Effects of a selenium-enriched diet on antioxidant response in adult crayfish (Procambarus clarkii)

Many diets employed in aquaculture are enriched with selenium to improve the diet quality and its conservation. The aim of the study was to investigate the effects of a diet enriched in selenium (1.21 mg kg(-1)) on the antioxidant response of Procambarus clarkii (Girard, 1852). Crayfish fed a diet with lower selenium content (0.30 mg kg(-1)) were the control. Selenium accumulation, enzymatic activities, and total glutathione were evaluated in hepatopancreas of adults of both sexes fed with both diets for 50 days at two experimental times (T(30), T(50) days). Treated females exhibited the highest selenium bioaccumulation during both experimental times, while treated males displayed the highest selenium concentration after 30 days, compared to control crayfish. A sex-related difference was found for the response of the analyzed enzymes in the selenium diet-treated specimens. In fact, superoxide dismutase, glutathione peroxidase and glyoxalase I activities in males were more sensitive compared with females, showing depleted activities in both experimental times. Catalase activity was induced in females (T(50)), while glutathione S-transferase activity was the highest in treated females and the lowest in treated males, compared with own controls. Only glutathione reductase activity and glutathione content showed the same trend in both sexes, which were both lowered in treated specimens, when compared with control crayfish. This result might be due to the effect of selenium toxicity on this freshwater species. Males and females of P. clarkii showed a different susceptibility to the prooxidant effects in a Se-enriched diet.     

Biological removal of gaseous ammonia in biofilters: space travel and earth-based applications

Gaseous NH3 removal was studied in laboratory-scale biofilters (14-L reactor volume) containing perlite inoculated with a nitrifying enrichment culture. These biofilters received 6 L/min of airflow with inlet NH3 concentrations of 20 or 50 ppm, and removed more than 99.99% of the NH3 for the period of operation (101, 102 days). Comparison between an active reactor and an autoclaved control indicated that NH3 removal resulted from nitrification directly, as well as from enhanced absorption resulting from acidity produced by nitrification. Spatial distribution studies (20 ppm only) after 8 days of operation showed that nearly 95% of the NH3 could be accounted for in the lower 25% of the biofilter matrix, proximate to the port of entry. Periodic analysis of the biofilter material (20 and 50 ppm) showed accumulation of the nitrification product NO3- early in the operation, but later both NO2- and NO3- accumulated. Additionally, the N-mass balance accountability dropped from near 100% early in the experiments to approximately 95 and 75% for the 20- and 50-ppm biofilters, respectively. A partial contributing factor to this drop in mass balance accountability was the production of NO and N2O, which were detected in the biofilter exhaust.     

Toxicity of trichlorotoluene isomers: a 28-day feeding study in the rat

Groups of 10 male and 10 female rats were fed alpha,alpha,alpha-, alpha,2,6- or 2,3,6- trichlorotoluene (TCT) in their diet at 0, 0.5, 5.0, 50 or 500 ppm for 28 days. Growth rate and food consumption were not affected by treatment. No deaths occurred. Significant increases in liver weights were observed in male rats fed 5.0 and 500 ppm 2,3,6-TCT. Mild serum biochemical changes occurred in male rats. These included increased SDH activities in the groups fed 5.0 and 50 ppm alpha, alpha, alpha-TCT, and 5.0 ppm 2,3,6-TCT. Alpha, alpha, alpha-TCT at 500 ppm caused elevated LDH activities in male rats. Hepatic microsomal aminopyrine N-demethylase activities were increased in male rats fed 500 ppm alpha,2,6-TCT. Hematological parameters were not affected by treatment. Mild histological changes were seen in the liver, kidney and thyroid of treated rats. Data presented here suggest that alpha, alpha, alpha-, alpha,2,6- and 2,3,6-TCT possess a low order of oral toxicity in the rat.     

Efficacy of the botanical extract (myrrh), chemical insecticides and their combinations on the cotton leafworm,Spodoptera littoralis boisd (lepidoptera: Noctuidae)

Abstract

Effects of the botanical extract (myrrh), Commiphora molmol, and the sublethal treatments of profenofos/chlorofluazuron, fenvalerate and pyriproxyfen on the larvae of S. littoralis were investigated. The results showed that myrrh induced the highest activity after 7 days of treatment with concentration of 10000 ppm and the percentage of mortality reached 44.4%. The chemical insecticide profenofos/chlorofluazuron appeared to be the most effective treatment, giving a mortality of 54% after one day of treatment with a concentration of 100 ppm. Different treatments showed adverse effects on pupation, emerging adults and larval duration. The highest concentration of myrrh (10000 ppm) induced 35% pupation. No pupa was obtained with profenofos/chlorofluazuron while fenvalerate and pyriproxyfen gave 13.3% at 50 ppm. At 10000 ppm of myrrh, 25% adult was emerged, also fenvalerate and pyriproxyfen decreased the emerging moth to 13.3% at 50 ppm. For control there was no larval mortality at 7 days and the percentages of pupation and adult emergence were 90%. Bioassays were also conducted to test the joint action of myrrh applied in binary mixtures with each chemical insecticide on Spodoptera larvae. Results of the bioassay of mixtures indicated antagonistic effects on larval mortality. However, combination of myrrh with profenofos/chlorofluazuron showed additive effect. Also, the degree of pupation and emerging moth varied considerably when myrrh combined with the chemical insecticides. The present work shows the strong efficacy of the botanical extract (myrrh) which could be used alone or in combination with sublethal doses of certain insecticides to control the cotton leafworm.